Charmed MySQL K8s How-To | Deploy in an airgapped environment

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Deploy in an offline or air-gapped environment

An air-gapped environment refers to a system that does not have access to the public internet. This guide goes through the special configuration steps for installing Charmed PostgreSQL k8s in an air-gapped environment.

Requirements

Canonical does not prescribe how you should set up your specific air-gapped environment. However, it is assumed that it meets the following conditions:

  • A K8s cluster is running.
  • DNS is configured to the local nameservers.
  • Juju is configured to use local air-gapped services.
  • The store-admin tool is installed and configured.
  • Air-gapped CharmHub is installed and running.
  • Local APT and LXD Images caches are reachable.
  • An air-gapped container registry (such as Artifactory) is reachable from the K8s cluster over HTTPS
    • Note: Secure (HTTPS) OCI access is important, otherwise Juju won’t work!

Air-gapped concept summary

  1. Export
  2. Transfer
  3. Import
  4. Deploy

Air-gapped day-to-day example

1. Exporting K8s Charms and OCI Resources are currently independent processes.

Sseveral improvements are planned: #1, #2

1.1. Charm. The necessary charm(s) can be exported as bundle OR independently (charm-by-charm). The special store-admin tool is designed to simplify the process. At the moment exporting of Charms and OCI resources are separated, but in the future the store-admin export could export all necessary OCI resource(s)) from official CharmHub.

At the moment, the store-admin exports (and includes into the blob) all the OCI resources metadata only:

store-admin export bundle mysql-k8s-bundle --channel=8.0/edge --series=jammy --arch=amd64
Example output 
> store-admin export bundle mysql-k8s-bundle --channel=8.0/edge --series=jammy --arch=amd64
Downloading mysql-k8s-bundle revision 45 (8.0/edge)
  [####################################]  100%
Downloading data-integrator revision 71 (edge)
  [####################################]  100%          
Downloading grafana-agent-k8s revision 93 (edge)
  [####################################]  100%          
Downloading resources for grafana-agent-k8s
Downloading oci-image resource agent-image revision 45
  [####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'agent-image' in charm 'grafana-agent-k8s'.
Downloading mysql-k8s revision 201 (8.0/edge)
  [####################################]  100%          
Downloading resources for mysql-k8s
Downloading oci-image resource mysql-image revision 113
  [####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'mysql-image' in charm 'mysql-k8s'.
Downloading mysql-router-k8s revision 164 (8.0/edge)
  [####################################]  100%          
Downloading resources for mysql-router-k8s
Downloading oci-image resource mysql-router-image revision 57
  [####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'mysql-router-image' in charm 'mysql-router-k8s'.
Downloading mysql-test-app revision 63 (edge)
  [####################################]  100%          
Downloading s3-integrator revision 59 (edge)
  [####################################]  100%          
Downloading self-signed-certificates revision 200 (edge)
  [####################################]  100%          
Downloading sysbench revision 78 (edge)
  [####################################]  100%          
Successfully exported charm bundle mysql-k8s-bundle: /home/ubuntu/snap/store-admin/common/export/mysql-k8s-bundle-20241006T231254.tar.gz

1.2. OCI: for the manual OCI export, please follow the official CharmHub guide.

2. Transfer the binary blobs using the way of your choice into Air-gapped environment.

cp /home/ubuntu/snap/store-admin/common/export/mysql-k8s-bundle-20241006T231254.tar.gz /media/usb/
...
cp /media/usb/mysql-k8s-bundle-20241006T231254.tar.gz /var/snap/snap-store-proxy/common/charms-to-push/

Note: always check checksum for the transferred blobs!

3. Upload the charm blobs into local Air-gapped CharmHub:

sudo snap-store-proxy push-charm-bundle /var/snap/snap-store-proxy/common/charms-to-push/mysql-k8s-bundle-20241006T231254.tar.gz

Note: when re-importing charms or importing other revisions, make sure to provide the --push-channel-map.

4. Upload the charm OCI into local Air-gapped OCI registry.

For the manual OCI import, please follow the official CharmHub guide.

5. Deploy and enjoy Juju charms the usual way:

juju deploy mysql-k8s --trust

Note: all the Air-gapp-deployed charms revisions and OCI resources tags/revisions must match the official CharmHub revisions/tags (users can rely in the official release notes).

Additional links: